Atomic Structure

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Atomic Structure

• Mr. Brudelie

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Early History

• Greeks first discovered it 2,500 yrs ago
• Noticed when amber was rubbed it became charged
  and other materials would be attracted to it
• Greeks called amber elecktron
• Work electric derived from it and meant amber
  like (have ability to attract other objects)

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• Early 1600s, William Gilbert found that amber was
  not the only material that could be charged and
  attract other objects
• Called materials that could be charged electriks
• Materials that could not be charged called
  nonelectriks

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• Frenchman Charles DuFay found that charged glass
  would attract some objects and repel others
• Soon learned the forces of repulsion and
  attraction

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List A List B
Glass (rubbed on silk) Glass (rubbed on wool Mica (rubbed on cloth) Asbestos (rubbed on cloth or paper) Stick of sealing wax (rubbed on wool Most kinds of rubber (rubbed on wool or cloth) Block of sulfur (rubbed on wool or fur) Sealing wax (rubbed on silk, wool, or fur) Mica (rubbed on dry wool) Amber (rubbed on cloth)
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• Benjamin Franklin named materials in list A
  positive
• Materials in list B negative

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Atoms

• The atom is the building block of the universe
• All matter is made from a combo of atoms
• Matter is anything that has mass and occupies
  space
• It can exist in 3 states solid, liquid, or gas
• Examples Ice, water, steam
• An element is a substance that cant be
  chemically divided into 2 simpler substances

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Periodic Table
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• An atom is the smallest part of an element
• The 3 parts of an atom are the electron, the
  neutron, and the proton
• Proton charge
• Electron - charge
• Neutron no charge
• Proton and Neutron found in nucleus of atom
• Atomic Number is the same as the number of
  protons in the nucleus

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• The electron orbits the outside of the nucleus
• An electron is 3 times larger than a proton
• Diameter of proton 0.07 trillionth of an in.
• Diameter of an electron 0.22 trillionth of an
  in.
• But the proton weighs 1840 times more

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The Law of Charges

• Opposite charges attract and like charges repel

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Centripetal Force

• Prevents an object from pulling away from its
  axis point although it wants to continue in a
  straight line

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• A conductor allows electrons to flow through it
• Silver, copper, and gold are all excellent
  conductors of electricity
• Silver is the best natural conductor, then
  followed by copper, gold, and aluminum

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• Electrical current is the flow of electrons
• Produced when an electron from 1 atom knocks into
  another electron
• They continually pass energy
• Example Pool

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Insulators

• Insulators are materials that resist the flow of
  electricity (electrons)
• Examples rubber, plastic, glass, and wood
• Semiconductors are neither good conductors or
  insulators
• Examples silicon and germanium
• Silicon used more b/c resists heat

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6 Methods of Producing Electricity

• 1. Magnetism
• 2. Chemical Action
• 3. Pressure
• 4. Heat
• 5. Friction
• 6. Light

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Magnetism

• Most common method to produce electricity
• Used in all generators and alternators
• Chemical Action
• Involved the movement of ions instead of just
  electrons (batteries)
• Pressure
• Uses striking, bending, or twisting crystals
  (quarts crystals watches, electronic ignitions)

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• Heat
• Uses thermocouples (pilot lights in appliances)
• Friction
• Static charges occur when certain materials
  rubbed together
• Light
• Photons produced when electrons forced to change
  to lower energy levels (gas filled lights-sodium
  vapor, neon lights)

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Summary

• Smallest part of an element?
• 3 principal particles of an atom?
• What charge do protons, electrons, and neutrons
  each have?
• What are conductors and made of what materials?
• What are insulators and made of what materials?
• 6 basic methods of producing electricity?